01
Sergi Bonastre Tomàs
Founder · Principal engineer
Sergi opened the studio in 2014 after seven years across two Barcelona platforms and one in London. He still writes Postgres queries by hand because he prefers it that way.
About the studio
Five engineers, one long table, Sarrià-Sant Gervasi.
CoreDevStructure was founded in 2014 by Sergi Bonastre — at the time, a single engineer renting a desk above a bookshop. The studio has grown to five engineers and a designer. The desk count went up; the office got rebuilt; the rule about not deploying on Fridays survived everything.
DOC. ID
CDS-PRA-001
- REV
- 7.4
- STATUS
- in production
- LAST REVIEW
- 2026-06-12
- FOUNDED
- 2014
- TEAM
- 5 + 1
§ 01 A note from the founder
CDS-FOUNDER.md
In 2014 I was four years into a backend engineering job at a Barcelona logistics platform when I realised the parts of the work I enjoyed were not the parts the job was paying for. I was paid to ship features. I enjoyed reading other people's repositories and writing the architecture decision records nobody had thought to write.
CoreDevStructure started the next year above a bookshop in Sarrià, with two desks, one Postgres book, and a single client — a wine importer who had inherited a Magento install. I rebuilt their checkout in a quarter and they referred us to two more clients. The studio has grown roughly one engineer every two years since.
I still write the slow Postgres queries by hand. I still review every architecture decision record before it leaves the studio. The size of the team has changed; the rules of the table have not.
— Sergi Bonastre Tomàs, Founder
§ 02 Engineers
CDS-ROSTER.csv
02
Júlia Ràfols Beneyto
Lead frontend engineer
Júlia leads our frontend practice. She has shipped three of the studio's six headless commerce builds and runs the design-system review on every engagement.
03
Pau Carmona Vives
Backend lead · DevOps
Pau is responsible for whether production stays up. He runs our incident response, our quarterly upgrade walks, and our internal "two strikes" rule for flaky tests.
04
Mar Esteve Bertolín
UX engineer · design systems
Mar sits on the line between design and code. She builds and maintains the studio's shared design tokens, the accessibility test fixtures, and the shape of every checkout we ship.
05
Ricard Cabré Sala
Senior fullstack
Ricard is the studio's utility player — equally comfortable in a Postgres EXPLAIN and a TypeScript generic. He runs every audit we deliver.
§ 03 Build pipeline
CDS-PIPELINE.yml
A pipeline, not a sales deck.
Six phases tagged in semver, from discovery to ongoing. Most engagements run between weeks 0 and v1.0 in 14 to 18 weeks of calendar time.
Discovery
1 week
A working session with three of your people, an audit of what exists, and a written brief that everyone signs.
Architecture
1 week
Architecture decision records, a wireframe of the data model, and a deployment topology you can hand to a junior.
Foundations
1 week
Repository, CI, deploy pipeline, observability, and the empty version of every page. Boring, on purpose.
Build
4 → 12 weeks
Feature by feature against the contract. Every Friday a demo. Every Tuesday a planning. Nothing dramatic.
Production
1 week
Go-live, runbooks, rollback rehearsal, and the first week of office hours sat next to your team.
Ongoing
Continuous
Either a retainer with us, or a clean handover to your team — your choice. We run a 90-day after-care window either way.
§ 04 The atelier
CDS-OFFICE.md
Carrer del Camp, 74. Two floors above a bookshop.
The studio runs out of an 80 m² loft in Sarrià-Sant Gervasi — five desks, one whiteboard wall, a long table for working sessions, and a kettle that has outlived three customer pivots. We meet visitors here on Wednesdays, by appointment, and on Zoom every other day of the week.