Markus Sintonen
Staff Software Engineer at ŌURA
Helsinki, Mainland Finland
Summary
👤
Senior🎓
Top SchoolMarkus Sintonen is a Staff Software Engineer in Helsinki with 11 years of experience building high-performance backend systems and hybrid stacks spanning C#, .NET, Ruby on Rails, Node.js/TypeScript, PostgreSQL, and React. At ŌURA he architects critical backend services; previously he led reporting backend development at Smartly.io for a multi‑terabyte, Citus‑sharded analytical platform driven by a JSON query language. He brings deep systems and performance expertise—demonstrated by open‑source contributions to Npgsql where he optimized connection pooling and fixed subtle concurrency bugs. His background in process control and near‑real‑time industrial systems informs a pragmatic approach to reliability and optimization under tight latency constraints. Known for moving complex, data‑intensive features from prototype to production, he pairs hands‑on coding with architectural leadership.
11 years of coding experience
7 years of employment as a software developer
Master of Science (M.Sc.), Process control and automation, 4.3 (scale 0-5), Master of Science (M.Sc.), Process control and automation, 4.3 (scale 0-5) at Aalto UniversityDanmarks Tekniske UniversitetFinnish Matriculation Examination, Finnish Matriculation Examination at Helsingin luonnontiedelukio
English, Finnish
Github Skills (11)
net10
asp-net10
databases10
dotnet-new10
dotnet10
postgresql10
csharp10
npgsql10
concurrency10
database10
performance-optimization9
Programming languages (9)
Github contributions (5)
npgsql/npgsql
Jul 2016 - Jul 2016
Npgsql is the .NET data provider for PostgreSQL.
Role in this project:
Back-end Developer
Back-end DeveloperContributions:7 commits, 6 PRs, 33 comments in 5 days
Contributions summary:Markus primarily focused on improving the concurrency and efficiency of the connection pool manager within the Npgsql library. Their contributions included optimizing the pool manager's performance by moving operations outside locks and preallocating lists. They also addressed and fixed a bug related to the pruning timer, ensuring correct behavior across connection pools. The user made changes to the connection string parsing and constructor to avoid unnecessary operations.
dotnetnpgsqlpostgresqldatabasepostgres
MarkusSintonen/pydantic
Feb 2023 - Feb 2025
Data parsing and validation using Python type hints
Contributions:275 pushes, 19 branches in 2 years
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