Sphera
Data Developer
Cut production build time by 30% by rewriting the SQL an ORM was silently generating
C# and Entity Framework mapping specifications, rewritten so the generated SQL looked like something a DBA would actually recommend. Verified data integrity before and after so the win didn't quietly change behaviour.
The problem
Production builds were slow enough to hurt developer productivity across the team. The existing data-access layer was making more round-trips than the queries required, and the default query shape Entity Framework generated was not the shape a DBA would have written by hand.
The approach
Developed mapping specifications in C# using Entity Framework to optimise the data access pattern.
Read the SQL Entity Framework actually generated behind the scenes, rewrote the mappings so the output looked like something a DBA would sign off on, and used efficient SQL to maintain and verify the data.
Verified data integrity before and after every change so the optimisation did not quietly change behaviour.
The outcome
Production build time down 30%.
Overall software development efficiency improved.
Behavioural equivalence held across the changed data-access surface.
What I take from this
ORMs quietly generate the query they are going to generate whether the shape is right or not. The 30% came from reading the actual SQL, not the C# that produced it. The same lesson applies to LLM-generated code today: read the output, not just the prompt.