Jan Dolezel
Principal Software Engineer at eithel.net
Prague, Prague, Czechia
Summary
🤩
Rockstar🎓
Top SchoolJan Dolezel is a Principal Software Engineer based in Prague with 11 years of professional experience focused on performance-sensitive desktop and cloud applications. At Microsoft he leads memory-regression detection and mitigation for Teams, collaborating across Edge, Monarch and M365 teams to innovate monitoring and reduction strategies. He combines deep backend and database experience—contributing to node-pg-migrate improvements around schema handling and migration integrity—with front-end type-safety work in DefinitelyTyped to strengthen large ecosystems. A pragmatic team lead and longtime freelancer, Jan has a track record of shipping production systems, integrating third‑party services, and improving code quality across full-stack projects. An interesting detail: he moves fluidly between low-level diagnostics and developer-facing type tooling, bridging operational reliability and developer ergonomics.
11 years of coding experience
17 years of employment as a software developer
Ing., Informatika a výpočetní technika, Ing., Informatika a výpočetní technika at České vysoké učení technické v PrazeInformatika, Informatika at Univerzita Karlova v Praze
English, Czech
Stackoverflow
36reputation
3kreached
3answers
0questions
Github Skills (16)
database-migrations10
type-system10
typescript10
javascript10
database-migration10
typescripts10
typesc10
postgresql10
sql10
typescript-types10
react10
type-definition9
database-design9
nodejs9
eslint8
Programming languages (5)
Github contributions (5)
salsita/node-pg-migrate
Mar 2016 - Nov 2020
Node.js database migration management for PostgreSQL
Role in this project:
Back-end Developer & Database Engineer
Back-end Developer & Database EngineerContributions:2 reviews, 515 commits, 540 PRs in 4 years 9 months
Contributions summary:Jan contributed to database migration management for PostgreSQL. Their work focused on fixing the order of migrations during the down process and fixing ESLint rules, indicating a focus on code quality and database integrity. They also implemented features for handling schemas and constraints, including the addition of primary keys and the ability to comment on columns within the database schema. Furthermore, the user made improvements such as closing the database connection after the migration runs and supporting the definition of expression generated columns.
migratordatabase-migrationsschema-migrationsprogramablemigration-tool
DefinitelyTyped/DefinitelyTyped
Sep 2018 - Nov 2020
The repository for high quality TypeScript type definitions.
Role in this project:Full-stack Developer
Full-stack DeveloperContributions:7 reviews, 16 commits, 14 PRs in 2 years 2 months
Contributions summary:Jan primarily contributes to the repository by fixing and updating TypeScript type definitions for the `react-sortable-tree` library. They also add type definitions for `redux-sentry-middleware` and `multy`, demonstrating a focus on integrating libraries and improving the type safety of the project. Furthermore, the user addressed linting issues and provided a theme for `react-sortable-tree-theme-file-explorer`. This indicates a focus on component and integration enhancements within a larger ecosystem.
typescript-definitionstype-definitionshigh-qualitydtsdefinitions
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