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Backend systems that keep running
9 years of programming. I design backend systems to be cheap to run and easy to change, whatever the stack.
Teams I've worked with
9 years
of programming and building production platforms
20+
projects completed
6+
companies and teams I've worked with
3
peer-reviewed papers
Services
How I can help
Backend systems
APIs, data models, billing, and access control, on whichever stack fits the team and the constraints.
Full-stack delivery
When the product needs a front end, I build it and own delivery from schema to deployment.
Technical review
Architecture reviews and migration plans for existing systems, such as moving a legacy platform to a new stack.
Selected work
Selected case studies
Each one covers the problem, the constraints, the tradeoffs, and what happened after launch.
“What I like about him is his dynamism; he is constantly updating his knowledge and always looking to optimize his results!”
Henrique MukandaCo-founder and Deputy Chief Executive Officer at Itot Africa
“Very friendly and smart, Bernard is passionate about web development, working and learning from him have been easy. Great developer”
Uriel BalelaSoftware Developer at Silicon Overdrive PTY (LTD)
“Bernard Ngandu is a talented young man, he never ceased to surprise me by his flexibility, his adaptation and his mastery in web programming, a major asset for large projects.”
Kileshe KasomaVice President, Ukamili Digital City
Writing
Engineering notes from production work
Write-ups on architecture, deployment, and data layers, drawn from systems I've shipped.
July 24, 2026
Building billing infrastructure with FlexPay and Symfony
How to build a durable payment workflow around FlexPay using Orders, Payment Transactions, signed webhooks, idempotent fulfillment, and a migration path from a legacy billing model.
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July 23, 2026
Modeling business rules with domain exceptions in Symfony
Using named domain exceptions to express rejected business rules, roll back commands, cross Symfony Messenger safely, produce RFC 9457 problem responses, and separate expected failures from real incidents.
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July 23, 2026
Testing DDD applications with Behat and in-memory adapters
A practical testing architecture for combining fast domain tests, executable Behat application specifications, in-memory ports, deterministic time, real Symfony boundaries, and focused infrastructure tests.
Read
Research
View researchResearch alongside the engineering
Peer-reviewed research in applied computing, published in journals and conference proceedings.
Video
Latest YouTube video
Dans cette vidéo, nous explorons en détail les fonctionnalités inédites, les optimisations et les changements majeurs que cette nouvelle version apporte. Rejoins-moi pour transformer tes compétences Symfony ! N'oublie p…
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