February 2026 (chatmail/core): Delivered reliability, security, and performance improvements with a focus on reproducible builds, dependency health, and release readiness. Implemented hardened CI checks, updated core dependencies to address advisories, improved runtime performance and logging, and fixed configuration edge cases that impact deployment and user experience. Prepared the codebase for upcoming releases (2.40.0–2.43.0), strengthening maintainability and risk posture.

January 2026 highlights: Implemented API-level access control with the who_can_call_me option; improved cryptographic flexibility by using the preferred hash algorithm for PGP signing; enhanced device messaging and folder handling to boost performance and privacy; expanded test coverage with a regression test for vc-request decryption; and completed reliability and privacy fixes that reduce IMAP/DNS-related issues. These deliverables strengthen security posture, reliability of mail flows, and readiness for upcoming releases. Technologies demonstrated include the Rust 1.93 toolchain, dependency upgrades (e.g., lru 0.12.5 with RUSTSEC-2026-0002 exception), CI automation, and provider database maintenance.

December 2025 performance summary focusing on delivering business value through release automation, reliability improvements, security hardening, and cross-repo collaboration across chatmail/core and deltachat/deltachat-android.

November 2025 (2025-11) - Deltachat Desktop (deltachat-desktop). Focused on enhancing onboarding with domain-based credential generation and reducing server dependencies. Implemented client-side credential generation for dcaccount, removing the HTTPS request from the default onboarding flow. Updated configuration and environment variables to reflect the shift. Result: faster onboarding, simpler deployment, and improved scalability of the onboarding path.

October 2025 monthly summary focused on delivering business value through release readiness, reliability improvements, API/UX enhancements, security hygiene, and QA coverage across core, Android, and desktop clients.

September 2025 monthly summary focused on hardening the platform, API modernization, and release readiness across chatmail/core and deltachat-desktop. Key outcomes include deprecating legacy verified_one_on_one_chats and e2ee_enabled configs; stabilizing the DC chat protection API; codebase cleanup through API/messaging utilities refactors; expansion of JSON-RPC API with CallState and has_video, plus ICE servers access; robust QR handling; and extensive release prep for 2.13.0/2.14.0/2.15.0 accompanied by CI improvements. Deliverables improve security posture, developer experience, and business readiness with clearer APIs and more reliable messaging flows.

August 2025 performance summary for chatmail/core and deltachat-android focused on strengthening security, reliability, and release readiness while improving developer productivity. Key features delivered include cross-chat resent messages (no longer required to originate from the same chat), Autocrypt header protections to bolster privacy, and Autocrypt-Gossip integration with message assignment by issuer fingerprint, plus verification support. A comprehensive color system overhaul was completed, switching to OKLCh with fingerprint-based color generation for consistency and accessibility. API surface reductions were implemented by removing Protected Chats APIs and related checks. Release readiness advanced with upgrade-related CI improvements, including the Rust toolchain, and Android platform support updates. These changes collectively improve user privacy, data integrity, and system maintainability while enabling smoother releases and platform compatibility.

July 2025 monthly summary for chatmail/core focusing on business value and technical achievements. Key features delivered include API exposure and test coverage that improve client integration reliability and QA feedback. Major bug fixes reduce risk in message handling, MDN processing, and error propagation. Release readiness activities advanced multiple versions (2.0.0 through 2.9.0), enabling smoother deployments. Observability and stability improvements were implemented to enhance operational visibility and resilience in IMAP fetch flows and background account synchronization. Technologies and skills demonstrated span Rust async patterns, API design, test automation, release engineering, and performance/logging instrumentation.

June 2025 monthly summary for chatmail/core: Delivered a cohesive set of security, onboarding, API simplification, reliability, observability, and release-readiness improvements. These changes strengthened data privacy, streamlined user onboarding, reduced API surface for maintainability, enhanced runtime stability, and improved visibility for debugging and releases. The work aligns with business goals of stronger security, faster user onboarding, and more predictable deployments.

May 2025 focused on reliability, platform readiness, and developer velocity across chatmail/core and deltachat-android. Key improvements target stability of core messaging, improved observability, and release readiness to enable safer and faster deliveries.

April 2025 performance summary for chatmail/core. Focused on expanding API surface, hardening test security, stabilizing core functionality, and accelerating release readiness to support upcoming production deployments. Delivered new API bindings for vcard handling, enhanced client APIs, comprehensive encryption in tests, and several stability and maintenance improvements that improve reliability, security, and developer velocity.

March 2025 highlights across chatmail/core and related DeltaChat repos focused on delivering business value through API expansion, stability hardening, and release/build reliability. Key features matured, security and reliability hardened, and the release process streamlined for faster time-to-market.

February 2025 monthly performance summary for chatmail/core and deltachat repositories. Focused on security hardening, reliability improvements, and cross-repo polish that drive security posture, data integrity, and faster release cycles. Notable outcomes include a parallel QR-code scanning feature, robust parsing/MIME fixes, file-operation reliability improvements, and readiness for internationalization and CI/release tooling upgrades.

January 2025 focused on delivering business value through reliability, performance, and release-readiness across chatmail/core and DeltaChat repos. Key outcomes include a new group consistency algorithm, improved self-message routing, expanded API capabilities, and tightened build/test pipelines. Notable improvements address message routing correctness, tombstone handling, and test stability, reducing support risk and accelerating future releases. Technical work spanned Rust, Nix, Python, and CI tooling, with emphasis on code quality and maintainability. Specific deliverables include: (1) new group consistency algorithm; (2) membership lifecycle: expire past members after 60 days; (3) JSON-RPC API to retrieve past members; (4) enhanced broadcast/list handling to restrict SetContacts sync to broadcast lists; (5) access control: non-members cannot modify member lists; (6) stability and robustness improvements in tests and error handling; (7) build/tooling upgrades and release preparation to enable faster and safer releases.

December 2024 monthly summary across chatmail/core and deltachat repos. Delivered meaningful business-value features, fixed critical bugs, improved reliability and performance, and advanced release-readiness across iOS and Android toolchains. Major wins include HTTP cache enhancements, API cleanup and refactor, optimized heartbeat handling, and updated documentation. Release readiness progressed with MSRV upgrades and release prep for 1.152.x, while dev tooling adjustments and maintainability improvements reduced future toil.

Monthly summary for 2024-11 focusing on business value, security, privacy, reliability, and developer efficiency across multiple repos. Key features delivered, major bugs fixed, and the overall impact are highlighted below, with technologies/skills demonstrated. Key features delivered: - deltachat-android: Privacy Enhancement — Disabled webview metrics collection to stop transmission of webview usage data (commit 6e135e06a96134e9db3fbbb8031b77b14d374f99). - chatmail/core: TLS hardening — Integrated Rustls for strict TLS and enabled TLS 1.3 session resumption; ALPN handling refactor to simplify identifiers (commits 3b2f18f9262d44470d128b4e3366e67544715d80, eb1bd1d200e5aed3ae137e8ee6c1cebdd5645de7, 460d2f3c2a3e94b681f5253c805f55ae9616af06). - chatmail/core: Deltachat REPL — Added send-sync command for improved sync operations (commit 176a89bd03fda86f99153aeaa6f3017bfd7e37cf). - deltachat-desktop: Draft safety — Do not clear draft on failed message send, preserving unsent drafts (commit dc5ffe5ee67e060f5b70823e03362beab5214e59). - Shared improvements: Tests cleanup and CI improvements, including removing print() calls in tests, nix target checks, formatting enforcement, and release preparation for upcoming versions (commits 800edc6fcefd11cf485b2eb118db012e39e0f5de, 47757c3c7fa5b14af2cec9e6b7c67db19b4cf75f, e117efa74495867b07400924dc42dade9cb84381, 10a05fa6d9472ddcaa9bfba6aeb7cbfa1c91162b, d2324a8fc4cd509dd852bc3f0c796c54f97d1442, 99330dd2de64ce9adbcb5231d072e6044def481e). - chatmail/core / documentation: Security and quality improvements — encryption of notification tokens, and documentation updates including style guide and peer_channels docs (commits 6dd8f44a15a451f4a3b69aaa0556e0bd3a19fcb9, 8967d7748cf3ff4031448a868b475f6d396da6d9). - Other core improvements: Code safety refactors removing unsafe indexing/slicing usage across modules to improve safety and readability (numerous commits across core modules). Major bugs fixed: - deltachat-android: Conversation Draft handling — Corrected draft validation to use draft.isOk() instead of null comparison (commit 9a4851961e1782365234de47d9f2b83dcf74ff0f). - chatmail/core: JSON-RPC robustness — Fixed get_chatlist_items_by_entries loading, and draft retrieval when referenced messages/drafts are deleted; improved resilience to deletions (commits 3a976a85801f47c87ed294672bd3cb05d055db1d, ea385fabae2384dc414e4492034f505718b01250, 7b98274681933367d871cfa06efc2bf4a9b7ea83). - deltachat-desktop: UI stability — Do not clear draft on failed send (commit dc5ffe5ee67e060f5b70823e03362beab5214e59). - deltachat/core: UI footer handling — Show Full Message footer fix to avoid failures when footers are missing (commit d9d694ead024825e65d6dd59648baa15b70b6933). - chatmail/core: Misc reliability fixes — Reverted some transient SMTP errors as permanent, and closed I/O endpoints safely when I/O stops (commits ff3efafcfc681cf2ebfa5d7cc44e842496b7745e, 4edade225c43e87fa0e059ca78f2f6782c37d971). Overall impact and accomplishments: - Strengthened privacy and security posture across Android and server components. - Improved reliability and user experience in chat and messaging flows through robust draft handling, chatlist loading, and footer UI fixes. - Accelerated release readiness and developer productivity via CI/tests improvements and a proactive release preparation workflow. - Enhanced code safety and maintainability through broad refactors removing risky indexing/slicing patterns and improving documentation. Technologies and skills demonstrated: - Rust and Rustls TLS hardening, TLS 1.3 session resumption, ALPN handling. - Android/Kotlin and desktop app stability improvements for user-facing features. - Repl tooling: new commands for streamlined operations. - Security: encryption of notification tokens; safe I/O handling. - Code quality and safety: extensive refactors to remove unsafe patterns and improve readability and correctness.

October 2024 (chatmail/core): Delivered key features and reliability improvements across real-time ads, gossip protocol, account privacy tagging, and CI/release readiness. These changes establish scalable, secure, and maintainable foundations with clear business value: improved real-time ad delivery reliability, larger and more robust gossip messaging, privacy tagging for accounts, IMAP/autoconfig reliability fixes, security upgrade, and streamlined release processes.

In August 2024, delivered foundational Android build stability and performance improvements across deltachat-android and chatmail/core. Key changes include Android NDK upgrades, dependency modernization, and build configuration refinements that enhance compatibility, performance, and maintainability on Android platforms. These changes reduce build failures, improve runtime behavior, and position the codebases for easier future upgrades.

Month: 2023-11 — chatmail/core focused update highlighting feature delivery, bug fixes, and technical achievements. Key features delivered: Chat Saved Messages Protection, which marks saved messages in chat as protected based on the contact's encryption preferences; includes tests verifying user-self protection behavior. Major bugs fixed: prevented protection messages from being added to the Saved Messages chat and corrected the first message timestamp to avoid mis-timestamping. Dependency upgrades: deltachat-jsonrpc JS dependencies updated to latest versions with adjusted package exports to improve type definitions and compatibility. Overall impact: enhanced privacy controls, corrected messaging semantics, and improved library compatibility, contributing to more reliable user experiences and maintainable code. Technologies/skills demonstrated: privacy-conscious feature design, test-driven development, encryption preference handling, dependency management and TypeScript/JavaScript packaging improvements.