Zbigniew Mandziejewicz
Lead Software Engineer at Agoda
Nagoya, Japan
Summary
👤
Senior🎓
Top SchoolZbigniew Mandziejewicz is a Lead Software Engineer with 16 years of experience building distributed, hybrid systems and leading teams across Europe and Asia from Nagoya. He brings deep, polyglot craftsmanship—Perl, Python, Scala, C++, and Go—applied to high-performance back-end systems, protocol-level work and cloud-native architectures. Zbigniew has repeatedly combined hands-on engineering with technical leadership, architecting order-management and HA IoT platforms, introducing 12-factor practices and driving developer productivity as an engineering manager and tech lead. An active open-source contributor, he has improved widely used projects such as the go-sqlite3 driver and go-jose JWT handling, and helped shape TypeScript typings for grpc-web to tighten client-server contracts. Beyond shipping code, he’s a developer advocate who surfaces gaps in stacks and processes to improve developer well-being and delivery at scale.
16 years of coding experience
14 years of employment as a software developer
Computer Science, Computer Science at Polish-Japanese Institute of Technology in WarsawZespol Szkol Elektryczych im. Tadeusza Kosciuszki w Opolu
English, Polish
Stackoverflow
51reputation
7kreached
2answers
0questions
Github Skills (28)
encrypt10
sqlite10
protocol-buffers10
web-token10
typescript10
json-web-signature10
c1110
c1710
go10
jsonwebtoken10
jwe10
typescript-types10
jwt10
typescripts10
grpc10
Programming languages (12)
Github contributions (5)
square/go-jose
Mar 2016 - Feb 2020
An implementation of JOSE standards (JWE, JWS, JWT) in Go
Role in this project:
Back-end Developer
Back-end DeveloperContributions:38 commits, 10 PRs, 61 comments in 3 years 11 months
Contributions summary:Zbigniew focused on enhancing the functionality of the `go-jose` library, specifically by implementing and refining claims encoding and decoding mechanisms. They worked on creating and modifying data structures like `StringOrArray` and `NumericDate` to conform to JSON Web Token (JWT) standards and incorporated validation logic for critical claims such as issuer, subject, audience, and expiry. Furthermore, the user introduced nested JWT support and updated claims to match the latest RFC standards.
golangsigningjosejson-web-tokenjwe
grpc/grpc-web
Nov 2018 - Feb 2019
gRPC for Web Clients
Role in this project:Back-end Developer
Back-end DeveloperContributions:16 commits, 11 PRs, 20 comments in 3 months
Contributions summary:Zbigniew primarily contributed to the generation of TypeScript typings for the gRPC-web project. Their work involved generating and refining `.d.ts` files to reflect the structure and data types used in the project. They addressed issues related to nested types, map types, and the inclusion of generated methods, ensuring the typings correctly represent the underlying protobuf definitions. Furthermore, the user fixed several bugs, including those related to the status events and byte array handling.
grpcjavascriptgrpc-webtypescriptclients
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