wireapp/wire-server
Oct 2024 – May 2026
20 Months active
Languages Used
BashCQLHTMLHaskellNginx configurationTextCMakefile
Technical Skills
API DesignBackend DevelopmentCassandraCode RefactoringDatabase Schema ManagementDevOps
Leif Battermann
PROFILE
Leif Battermann
Over 20 months, contributed to wireapp/wire-server by building and evolving backend systems for secure collaboration, team management, and API reliability. Delivered features such as domain registration migration to PostgreSQL, granular feature flagging, and robust channel and user group management, while modernizing data models and access controls. Applied Haskell and TypeScript to implement scalable APIs, event-driven architectures, and integration with technologies like RabbitMQ, Redis, and Cassandra. Focused on maintainability through modular programming, comprehensive testing, and CI/CD improvements. Enhanced security and auditability with refined authentication, SAML/SCIM integration, and detailed logging, supporting safer deployments and streamlined onboarding for enterprise environments.
Overall Statistics
Feature vs Bugs
71%Features
Repository Contributions
225Total
Bugs
44
Commits
225
Features
106
Lines of code
439,180
Activity Months20
Your Network
64 peopleSame Organization
@wire.com45
Akshay MankarMember
acv-wMember
Amit SagtaniMember
ap-ext-wireMember
Augusto César DiasMember
barisMember
Christoph AldrianMember
dariaoldenburgMember
David-HennerMember
Shared Repositories
19
Work History
May 2026
7 Commits • 3 Features
May 1, 2026In May 2026, wire-server delivered four core initiatives targeting data integrity, reliability, and security, with strong testing and governance improvements across the domain and group management subsystems. Key features delivered: - Domain Registration Infrastructure Improvements: Migrated domain registration data to PostgreSQL with a new schema, added safe migrations and testing support, and introduced migration locking safeguards to prevent deadlocks; testing API for domain registration endpoints. - Security Update: Remove Kyber Hybrid PQC Ciphersuite: Deprecated and removed Kyber-based hybrid post-quantum ciphersuite; updated cipher suite definitions and documentation accordingly. - Admin Group Governance Enhancements: Safeguards to prevent creating adminless groups; configuration options for promotion strategies and timeout settings; comprehensive tests. Major bugs fixed: - MLS Conversation Stability: Fixed inconsistent removal notifications between local and remote MLS members and improved handling of group information during conversation resets; improved error messaging when group state is missing. Overall impact and accomplishments: - Improved data integrity and migration safety for domain data, reducing deadlock risk and improving testability. - Strengthened security posture by removing unsupported ciphers and aligning documentation. - Enhanced governance and reliability for admin group management, with better protection against misconfigurations and clearer test coverage. - Demonstrated strong SQL/data engineering, cryptographic governance, and MLS group-management capabilities with an emphasis on business value and reliability.
7 Commits • 3 Features
May 1, 2026In May 2026, wire-server delivered four core initiatives targeting data integrity, reliability, and security, with strong testing and governance improvements across the domain and group management subsystems. Key features delivered: - Domain Registration Infrastructure Improvements: Migrated domain registration data to PostgreSQL with a new schema, added safe migrations and testing support, and introduced migration locking safeguards to prevent deadlocks; testing API for domain registration endpoints. - Security Update: Remove Kyber Hybrid PQC Ciphersuite: Deprecated and removed Kyber-based hybrid post-quantum ciphersuite; updated cipher suite definitions and documentation accordingly. - Admin Group Governance Enhancements: Safeguards to prevent creating adminless groups; configuration options for promotion strategies and timeout settings; comprehensive tests. Major bugs fixed: - MLS Conversation Stability: Fixed inconsistent removal notifications between local and remote MLS members and improved handling of group information during conversation resets; improved error messaging when group state is missing. Overall impact and accomplishments: - Improved data integrity and migration safety for domain data, reducing deadlock risk and improving testability. - Strengthened security posture by removing unsupported ciphers and aligning documentation. - Enhanced governance and reliability for admin group management, with better protection against misconfigurations and clearer test coverage. - Demonstrated strong SQL/data engineering, cryptographic governance, and MLS group-management capabilities with an emphasis on business value and reliability.
May 2026
April 2026
10 Commits • 3 Features
Apr 1, 2026April 2026 monthly summary for wire-server. Delivered substantive client subsystem enhancements and Federation API integration, strengthened API reliability and security, and improved deployment flexibility. Implemented remote user interactions and prekey bundle handling via refactors of FederationAPIAccess and Galley API Access, enabling more robust client management. Hardened API error handling with header normalization and safer password reset flows for SAML-authenticated users. Optimized deployment with optional Helm-based Wire proxy deployment and consolidation of galley.yaml into the background worker configuration. Resolved a push notification reliability issue by correcting the ordering of notification data structures. These changes improve business value through secure federation, scalable client management, safer auth flows, and streamlined deployments.
April 2026
10 Commits • 3 Features
Apr 1, 2026April 2026 monthly summary for wire-server. Delivered substantive client subsystem enhancements and Federation API integration, strengthened API reliability and security, and improved deployment flexibility. Implemented remote user interactions and prekey bundle handling via refactors of FederationAPIAccess and Galley API Access, enabling more robust client management. Hardened API error handling with header normalization and safer password reset flows for SAML-authenticated users. Optimized deployment with optional Helm-based Wire proxy deployment and consolidation of galley.yaml into the background worker configuration. Resolved a push notification reliability issue by correcting the ordering of notification data structures. These changes improve business value through secure federation, scalable client management, safer auth flows, and streamlined deployments.
March 2026
31 Commits • 12 Features
Mar 1, 2026March 2026: Delivered deployment simplifications and architectural enhancements for wire-server, with targeted fixes that improve reliability and observability. Key features delivered include consolidating helm charts, automating manifest rendering, advancing subsystems modularization, initiating Polysemy-based client subsystem groundwork, and upgrading tooling with nix-enabled Renovate. These efforts improved deployment confidence, scalability, and engineering productivity while addressing stability and API/documentation gaps across the surface.
31 Commits • 12 Features
Mar 1, 2026March 2026: Delivered deployment simplifications and architectural enhancements for wire-server, with targeted fixes that improve reliability and observability. Key features delivered include consolidating helm charts, automating manifest rendering, advancing subsystems modularization, initiating Polysemy-based client subsystem groundwork, and upgrading tooling with nix-enabled Renovate. These efforts improved deployment confidence, scalability, and engineering productivity while addressing stability and API/documentation gaps across the surface.
March 2026
February 2026
8 Commits • 4 Features
Feb 1, 2026February 2026 monthly summary for wire-server focusing on business value and technical delivery. Delivered major enhancements to authentication, ephemeral user data handling, data migration, and deployment flexibility, with targeted fixes to IdP testing stability.
February 2026
8 Commits • 4 Features
Feb 1, 2026February 2026 monthly summary for wire-server focusing on business value and technical delivery. Delivered major enhancements to authentication, ephemeral user data handling, data migration, and deployment flexibility, with targeted fixes to IdP testing stability.
January 2026
16 Commits • 12 Features
Jan 1, 2026January 2026 highlights for wire-server: API evolution, data-layer modernization, and CI/stability improvements that drive reliability and speed to market. Key features delivered include finalizing API version 14 and introducing development version 15 with improved Swagger defaults; implementing per-user quota for CellsInternal; validating email templates and cleaning rendering; modernizing the migrations tooling and CI stability with a generalized migration lock; and migrating conversation codes from Cassandra to PostgreSQL. Major bugs fixed include CI failures in PostgreSQL migrations for backendA and migration default tuning for background workers. Overall impact: stronger API clarity, more scalable data model, safer deployments, and a cleaner, more modular codebase. Technologies demonstrated: OpenAPI/Swagger, PostgreSQL migrations tooling, Cassandra-to-PostgreSQL migration, HTTP/2 performance optimizations, CodeStore modularization and environment config cleanup, and a revamped feature flag architecture.
16 Commits • 12 Features
Jan 1, 2026January 2026 highlights for wire-server: API evolution, data-layer modernization, and CI/stability improvements that drive reliability and speed to market. Key features delivered include finalizing API version 14 and introducing development version 15 with improved Swagger defaults; implementing per-user quota for CellsInternal; validating email templates and cleaning rendering; modernizing the migrations tooling and CI stability with a generalized migration lock; and migrating conversation codes from Cassandra to PostgreSQL. Major bugs fixed include CI failures in PostgreSQL migrations for backendA and migration default tuning for background workers. Overall impact: stronger API clarity, more scalable data model, safer deployments, and a cleaner, more modular codebase. Technologies demonstrated: OpenAPI/Swagger, PostgreSQL migrations tooling, Cassandra-to-PostgreSQL migration, HTTP/2 performance optimizations, CodeStore modularization and environment config cleanup, and a revamped feature flag architecture.
January 2026
December 2025
6 Commits • 4 Features
Dec 1, 2025December 2025: The wire-server development effort centered on making API interactions clearer, improving internal configuration governance, and strengthening the architecture and toolchain. Delivered concrete features for domain registration configuration, internal cells management via a robust feature flag, and a centralized configuration subsystem, while upgrading core dependencies for stability and performance.
December 2025
6 Commits • 4 Features
Dec 1, 2025December 2025: The wire-server development effort centered on making API interactions clearer, improving internal configuration governance, and strengthening the architecture and toolchain. Delivered concrete features for domain registration configuration, internal cells management via a robust feature flag, and a centralized configuration subsystem, while upgrading core dependencies for stability and performance.
November 2025
14 Commits • 5 Features
Nov 1, 2025November 2025 wire-server monthly summary. Delivered robust channel management and API ecosystem enhancements, with a focus on business value and reliability. Key outcomes include: (1) Channel management features: a case-insensitive channel search API with a dedicated endpoint and supporting Nginx path fixes, plus changelog updates. (2) Channel governance: a new channel membership replacement endpoint with admin permissions enforcement, accompanied by tests and OpenAPI/docs updates. (3) Operational efficiency: a background job to synchronize user-group membership with channels, plus SCIM-based endpoint for programmatic user-group management. (4) API versioning and docs: finalized V13 and prepared for V14 with updated references. Stability and quality improvements: improved BrigAPIAccess error handling to avoid spurious 5xx on expected 2xx/404 responses and deflaked flaky tests; modular refactor to increase maintainability and future extensibility.
14 Commits • 5 Features
Nov 1, 2025November 2025 wire-server monthly summary. Delivered robust channel management and API ecosystem enhancements, with a focus on business value and reliability. Key outcomes include: (1) Channel management features: a case-insensitive channel search API with a dedicated endpoint and supporting Nginx path fixes, plus changelog updates. (2) Channel governance: a new channel membership replacement endpoint with admin permissions enforcement, accompanied by tests and OpenAPI/docs updates. (3) Operational efficiency: a background job to synchronize user-group membership with channels, plus SCIM-based endpoint for programmatic user-group management. (4) API versioning and docs: finalized V13 and prepared for V14 with updated references. Stability and quality improvements: improved BrigAPIAccess error handling to avoid spurious 5xx on expected 2xx/404 responses and deflaked flaky tests; modular refactor to increase maintainability and future extensibility.
November 2025
October 2025
4 Commits • 2 Features
Oct 1, 2025Concise monthly summary for wireapp/wire-server (2025-10): Delivered two core features to enhance auditing, team management, and API reliability; fixed critical gaps in user-group handling and API routing; improved test coverage and configurability; demonstrated strong collaboration with infra/ops for Helm-based options and Nginx rules.
October 2025
4 Commits • 2 Features
Oct 1, 2025Concise monthly summary for wireapp/wire-server (2025-10): Delivered two core features to enhance auditing, team management, and API reliability; fixed critical gaps in user-group handling and API routing; improved test coverage and configurability; demonstrated strong collaboration with infra/ops for Helm-based options and Nginx rules.
September 2025
14 Commits • 7 Features
Sep 1, 2025September 2025 performance summary focusing on backend reliability, observability, and scalable user workflows across wire-server. Delivered consolidated data access with ConversationStore, launched end-to-end User Groups API with routing, improved search accuracy and policy controls, introduced asset audit logging, and enhanced auditability via Federator IP forwarding. Also completed SCIM/E2EID alignment and documented federation changes. Achieved notable bug fix in team search role filtering. These efforts reduce data access complexity, improve security/auditability, and enable scalable, governance-aligned user-group workflows.
14 Commits • 7 Features
Sep 1, 2025September 2025 performance summary focusing on backend reliability, observability, and scalable user workflows across wire-server. Delivered consolidated data access with ConversationStore, launched end-to-end User Groups API with routing, improved search accuracy and policy controls, introduced asset audit logging, and enhanced auditability via Federator IP forwarding. Also completed SCIM/E2EID alignment and documented federation changes. Achieved notable bug fix in team search role filtering. These efforts reduce data access complexity, improve security/auditability, and enable scalable, governance-aligned user-group workflows.
September 2025
August 2025
10 Commits • 5 Features
Aug 1, 2025August 2025 at wire-server delivered core platform improvements enabling safer staged rollouts, granular feature control, and greater stability across migrations and messaging. Implemented an iOS Chat Bubbles feature flag to support staged UI rollouts; added Team-Level Apps Feature Configuration for per-team feature governance; introduced API versioning with V12 and finalized V11, aligning route definitions and tests. Enhanced PostgreSQL migration readiness with a single-transaction approach, improved error logging, and stabilized tests. Strengthened observability and resilience through RabbitMQ connection logging enhancements and error handling, reduced test flakiness with better reporting and WebSocket handling, and cleaned up unused event types to reduce noise. These changes collectively improve deployment safety, developer productivity, and system reliability, while expanding feature management capabilities for teams and safer migrations.
August 2025
10 Commits • 5 Features
Aug 1, 2025August 2025 at wire-server delivered core platform improvements enabling safer staged rollouts, granular feature control, and greater stability across migrations and messaging. Implemented an iOS Chat Bubbles feature flag to support staged UI rollouts; added Team-Level Apps Feature Configuration for per-team feature governance; introduced API versioning with V12 and finalized V11, aligning route definitions and tests. Enhanced PostgreSQL migration readiness with a single-transaction approach, improved error logging, and stabilized tests. Strengthened observability and resilience through RabbitMQ connection logging enhancements and error handling, reduced test flakiness with better reporting and WebSocket handling, and cleaned up unused event types to reduce noise. These changes collectively improve deployment safety, developer productivity, and system reliability, while expanding feature management capabilities for teams and safer migrations.
July 2025
20 Commits • 6 Features
Jul 1, 2025July 2025 — wire-server: Delivered governance-enabled channel and conversation enhancements, improved notification/typing reliability, API evolution readiness, infrastructure upgrades, and security/resilience improvements. This work enables safer, more scalable collaboration, reduces noisy alerts, future-proofs APIs, stabilizes deployments, and strengthens secure messaging across the platform.
20 Commits • 6 Features
Jul 1, 2025July 2025 — wire-server: Delivered governance-enabled channel and conversation enhancements, improved notification/typing reliability, API evolution readiness, infrastructure upgrades, and security/resilience improvements. This work enables safer, more scalable collaboration, reduces noisy alerts, future-proofs APIs, stabilizes deployments, and strengthens secure messaging across the platform.
July 2025
June 2025
13 Commits • 7 Features
Jun 1, 2025June 2025 at wire-server focused on reliability, security, and developer experience. Delivered major features including a Server Time API endpoint, User Group Membership event notifications, WebSocket/event system enhancements, Security/ACL improvements, and Channel Administration improvements. Fixed a critical data integrity issue in User Groups with foreign key constraint migrations and updated tests to reduce flakiness. Impact: stronger data integrity, improved client synchronization, safer admin workflows, and better observability. Technologies demonstrated: PostgreSQL migrations, ACLs, API eventing, WebSocket and RabbitMQ integrations, SAML flow adjustments, and test stability practices.
June 2025
13 Commits • 7 Features
Jun 1, 2025June 2025 at wire-server focused on reliability, security, and developer experience. Delivered major features including a Server Time API endpoint, User Group Membership event notifications, WebSocket/event system enhancements, Security/ACL improvements, and Channel Administration improvements. Fixed a critical data integrity issue in User Groups with foreign key constraint migrations and updated tests to reduce flakiness. Impact: stronger data integrity, improved client synchronization, safer admin workflows, and better observability. Technologies demonstrated: PostgreSQL migrations, ACLs, API eventing, WebSocket and RabbitMQ integrations, SAML flow adjustments, and test stability practices.
May 2025
4 Commits • 3 Features
May 1, 2025May 2025 performance highlights for wire-server: Delivered targeted feature work and critical fixes with a focus on security, admin control, data visibility, and platform compatibility. The month reinforced core business value by reducing risk, enabling granular feature management, and ensuring compatibility with modern Redis deployments.
4 Commits • 3 Features
May 1, 2025May 2025 performance highlights for wire-server: Delivered targeted feature work and critical fixes with a focus on security, admin control, data visibility, and platform compatibility. The month reinforced core business value by reducing risk, enabling granular feature management, and ensuring compatibility with modern Redis deployments.
May 2025
April 2025
11 Commits • 6 Features
Apr 1, 2025April 2025 focused on delivering a safer, more scalable API surface, stronger admin/channel governance, and more reliable notifications, while refreshing test infrastructure. Major outcomes include finalizing API v8, enabling v9 as default with docs, empowering admins with channel creation controls, enforcing external partner limits, improving notification routing, and maintaining test certificates.
April 2025
11 Commits • 6 Features
Apr 1, 2025April 2025 focused on delivering a safer, more scalable API surface, stronger admin/channel governance, and more reliable notifications, while refreshing test infrastructure. Major outcomes include finalizing API v8, enabling v9 as default with docs, empowering admins with channel creation controls, enforcing external partner limits, improving notification routing, and maintaining test certificates.
March 2025
28 Commits • 14 Features
Mar 1, 2025March 2025 wire-server monthly summary: Delivered key collaboration, authentication, and reliability improvements that enhance secure teamwork at scale. Major features include the launch of private channels, domain- and admin-controlled access enhancements, and an extensible add-permissions framework. Critical defects impacting MLS, production holds, and IdP/SCIM onboarding were resolved. The month also advanced federation reliability, CI/test hygiene, and release processes to reduce risk and improve developer efficiency. The work demonstrates strong DB schema evolution, new REST endpoints, robust test coverage, and a security-conscious approach to identity and access management.
28 Commits • 14 Features
Mar 1, 2025March 2025 wire-server monthly summary: Delivered key collaboration, authentication, and reliability improvements that enhance secure teamwork at scale. Major features include the launch of private channels, domain- and admin-controlled access enhancements, and an extensible add-permissions framework. Critical defects impacting MLS, production holds, and IdP/SCIM onboarding were resolved. The month also advanced federation reliability, CI/test hygiene, and release processes to reduce risk and improve developer efficiency. The work demonstrates strong DB schema evolution, new REST endpoints, robust test coverage, and a security-conscious approach to identity and access management.
March 2025
February 2025
6 Commits • 2 Features
Feb 1, 2025February 2025 — wire-server: Domain Registration and Activation Workflow delivered domain-based onboarding controls, including API support for GET/DELETE Registered Domains, activation rules based on domain status, and transitions between configurations ('no-registration' to 'backend'), with SSO optimizations when the domain is registered to a team. Initiated Dynamic Feature Store Migration with a Cassandra-backed dynamic features table, read-only during transition, and migration of existing features to the new 'barbie' feature system. Fixed Guest-to-Team Migration bug by preventing guest migrations, refactoring upgrade logic to allow upgrades only for active users not in a team, and adding tests. These changes improve security, scalability, and reliability of onboarding and feature delivery. Technologies demonstrated include Cassandra-backed feature stores, domain-based access controls, SSO optimization, and test-driven upgrade strategies.
February 2025
6 Commits • 2 Features
Feb 1, 2025February 2025 — wire-server: Domain Registration and Activation Workflow delivered domain-based onboarding controls, including API support for GET/DELETE Registered Domains, activation rules based on domain status, and transitions between configurations ('no-registration' to 'backend'), with SSO optimizations when the domain is registered to a team. Initiated Dynamic Feature Store Migration with a Cassandra-backed dynamic features table, read-only during transition, and migration of existing features to the new 'barbie' feature system. Fixed Guest-to-Team Migration bug by preventing guest migrations, refactoring upgrade logic to allow upgrades only for active users not in a team, and adding tests. These changes improve security, scalability, and reliability of onboarding and feature delivery. Technologies demonstrated include Cassandra-backed feature stores, domain-based access controls, SSO optimization, and test-driven upgrade strategies.
January 2025
7 Commits • 3 Features
Jan 1, 2025January 2025 monthly summary focusing on business value and technical achievements across wire-server. Key outcomes include governance-enabled domain management, API hygiene improvements, and stronger access controls, delivered with infra and tests integration.
7 Commits • 3 Features
Jan 1, 2025January 2025 monthly summary focusing on business value and technical achievements across wire-server. Key outcomes include governance-enabled domain management, API hygiene improvements, and stronger access controls, delivered with infra and tests integration.
January 2025
December 2024
6 Commits • 3 Features
Dec 1, 2024December 2024 monthly summary for wire-server focused on delivering authentication and enterprise readiness improvements, while stabilizing test and runtime environments. Key contributions spanned new SCIM IdP association, enterprise domain management, startup stability checks, team search correctness, and cross-system team activation synchronization. All work included accompanying test coverage and documentation updates to ensure maintainability and onboarding velocity.
December 2024
6 Commits • 3 Features
Dec 1, 2024December 2024 monthly summary for wire-server focused on delivering authentication and enterprise readiness improvements, while stabilizing test and runtime environments. Key contributions spanned new SCIM IdP association, enterprise domain management, startup stability checks, team search correctness, and cross-system team activation synchronization. All work included accompanying test coverage and documentation updates to ensure maintainability and onboarding velocity.
November 2024
5 Commits • 3 Features
Nov 1, 2024November 2024: Delivered three core features in wire-server that significantly improve onboarding, team management, and notification reliability. Implemented Team Owner Welcome Email Templates and Onboarding with multilingual (German/English) content, updated email subjects and HTML/text bodies, and replaced the personal user welcome with team-owner onboarding. Added Team Invitation Flow and Account Upgrade configuration, including routes for inviting/upgrading teams and accepting invitations, with fixes to personal user invitation URL config and related Helm chart adjustments. Modernized the Notification System with RabbitMQ, establishing exchanges/queues, dead-lettering, and updating clients to publish/consume via the queue-based system. Also performed targeted config and upgrade work to stabilize deployments and improve scalability. Business value: smoother onboarding for team owners, clearer invitation and upgrade workflows, and a scalable, reliable notification pipeline that supports growth with reduced operational risk.
5 Commits • 3 Features
Nov 1, 2024November 2024: Delivered three core features in wire-server that significantly improve onboarding, team management, and notification reliability. Implemented Team Owner Welcome Email Templates and Onboarding with multilingual (German/English) content, updated email subjects and HTML/text bodies, and replaced the personal user welcome with team-owner onboarding. Added Team Invitation Flow and Account Upgrade configuration, including routes for inviting/upgrading teams and accepting invitations, with fixes to personal user invitation URL config and related Helm chart adjustments. Modernized the Notification System with RabbitMQ, establishing exchanges/queues, dead-lettering, and updating clients to publish/consume via the queue-based system. Also performed targeted config and upgrade work to stabilize deployments and improve scalability. Business value: smoother onboarding for team owners, clearer invitation and upgrade workflows, and a scalable, reliable notification pipeline that supports growth with reduced operational risk.
November 2024
October 2024
5 Commits • 2 Features
Oct 1, 2024October 2024 performance summary for wire-server: Delivered three primary features and a critical test infra fix, enhancing user-facing email flows, identity management, and federation testing stability. These updates improved user experience, security posture, and development/test reliability, with clear traceability to commits.
October 2024
5 Commits • 2 Features
Oct 1, 2024October 2024 performance summary for wire-server: Delivered three primary features and a critical test infra fix, enhancing user-facing email flows, identity management, and federation testing stability. These updates improved user experience, security posture, and development/test reliability, with clear traceability to commits.
Activity
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Quality Metrics
Correctness91.6%
Maintainability87.0%
Architecture87.8%
Performance83.4%
AI Usage23.4%
Skills & Technologies
Programming Languages
ACLBashCC++CQLCabalClojureCqlDockerGo
Technical Skills
API DesignAPI DevelopmentAPI DocumentationAPI IntegrationAPI ManagementAPI TestingAPI designAPI developmentAPI integrationAPI testingAccess ControlAuthenticationBackend DevelopmentBug FixingBuild System Configuration
Repositories Contributed To
Overview of all repositories you've contributed to across your timeline