Skip to my experience
Skip intro ↘
FREN

Cédric Freret — Lead Software Engineer

I’m not throwing away the experience.
I’m throwing away the format that reduces it to a list.

Cédric Freret

Hands-on Lead Software Engineer · Paris area, hybrid

I take ownership of the whole challenge: clarify the need, shape the architecture, write critical code and see it through to production.

I’m not actively looking for a new role. If your team, product and challenge align with how I work, I’m open to a conversation.

Three situations · a one-minute read

Build a product, drive a high-stakes change, remove a business problem.

01 Examin · 2021 – 2023 · full-stack, then lead

Turn a complex domain into a usable product.

I translated compliance rules into user journeys, results and usable data, from the audit engine to its reports. I then led the entire interface redesign independently, delivering it in six months with no loss of functionality. As lead, I also mentored a junior developer and two interns through code reviews and pair programming.

My role, decisions and outcomes

Context

A private B2B product, small team, dense regulatory domain. February 2021 – October 2023.

My role

Full-stack developer, then lead from October 2022. Business engine, PDF generation, interface, Ansible IaC, monitoring and backups.

Mentoring one junior developer and two interns.

Decisions

Model the compliance rules inside the product engine.

Build a PDF rendering faithful to the web version's modules, tables and charts.

Carry the full interface redesign alone.

Make the infrastructure reproducible with Ansible, monitoring and backups.

Results & limits

Redesign delivered in six months, with no functional loss and no negative business impact identified.

After an attack: new server, infrastructure and data restored single-handed in under two hours, against more than a week previously.

This work predates my professional use of AI.

Full-stack · PDF rendering · Ansible · monitoring · backups

02 Fondation du patrimoine · since October 2023 · Lead Software Developer

Rebuild the foundations of a national donation platform while it stays in use.

I coordinate an external team of four. Our optimisation work proved itself during an unexpected TV-driven traffic spike: the platform held up, with no general outage. We also switched card payments — around 70% of donations — during the year-end campaign, the Foundation’s most important fundraising period.

My role, decisions and outcomes

Context

A national donation platform whose inefficient code required more infrastructure than it does today. We first improved the software to stabilise the service; that work now creates room to further reduce infrastructure capacity and costs.

My role

I help shape the roadmap and deliver on its commitments, making room for technical needs and debt reduction. I coordinate four external team members and remain hands-on with features, technical decisions, reviews and critical code.

Decisions

Optimise Next.js rendering, caching, images and page splitting. Verify origin capacity with load tests up to 250 requests/s.

Work with the team to switch card payments to the new provider in one cutover during the year-end campaign.

Results & limits

Performance under real traffic. On 19 July 2026, an unexpected TV-driven spike was handled with no general outage: 1,614 req/s at the CDN and ≈172 req/s at origin (distinct peaks). Rolling p95 reached 4.6 s during scaling.

Card payments during the key campaign. The cutover took place during year-end fundraising. One failed transaction was spotted, fixed and audited in under 24 hours.

Costs. Around €500/month already saved on third-party services within the documented scope. Further infrastructure downsizing is the next step. These results were achieved with the team.

Next.js SSR/ISR · CDN · caching · load testing · payment migration

03 French Ministry of the Interior · December 2017 – February 2021

From thirty hours to half a day. Every week.

By automating the statistical pipeline within the teams’ existing tools, I freed up roughly 0.75 full-time equivalent (FTE) of capacity for analysis. Weekly production fell from thirty hours to half a day; consolidation between reporting seasons, from two months to four days. Less repetitive handling, more time to understand the data.

My role, decisions and outcomes

Context

A statistical chain spread across departments, delegations and regions, run by hand: spreadsheets sent by email, repeated consolidation and corrections.

My role

Full-stack developer: designing and building the automation chain, working directly with the services that produce and use the data.

Decisions

Automate inside the tools already in place — C++, Qt, SQL, macros and scripts — rather than elsewhere. Treat the inter-season consolidation as a deliverable of its own.

Results & limits

Around 30 hours a week reduced to half a day, freeing roughly 0.75 FTE of capacity for analysis.

Estimated using a 35-hour week and a 3.5-hour half-day: (30 − 3.5) ÷ 35 ≈ 0.76 FTE. This is reallocated time, not a removed position.

Consolidation between reporting seasons fell from two months to four days.

C++ · Qt · SQL · macros · scripts

AI and judgement

AI widens what I can explore.
The judgement is still mine.

As the technical point of reference for AI, I help teams adopt it to spot problems earlier and make more room for domain expertise. The principle is the same as at the Ministry: automate repetitive tasks and leave decisions that require judgement to people.

  1. 01
    Frame the problem and the expected behaviour
  2. 02
    Generate several versions, compare their behaviour
  3. 03
    Test, review, measure against reality
  4. 04
    Correct, then own what ships

Spot issues before being asked. Each day, I cross-check feedback from emails and forms against logs and code to identify UX friction and bugs before they are brought to me. The practice is already in use; I’m still refining its structure.

Take automation into production. The Word/SharePoint → CMS workflow is deployed and in use, running largely on its own with human validation. Technical intervention centres on occasional script corrections.

Tools, safeguards and outcomes

Controlled data access. I built an SSO-secured MCP server that all employees can use through the Dust application, under the company’s contractual confidentiality framework. It connects agents to internal tools, including our CRM, which has no native MCP integration. Cross-checking user feedback, logs and code is one of its uses.

Verify and correct. During the team’s Strapi V3 → V5 migration, behaviour comparisons and repeated audits helped fix more than 60% of the regressions detected within that loop.

CMS workflow scope. Import, audit, notification, filing, then human validation. Across 500 records, the estimated potential is around 250 hours of avoided data entry; this remains an estimate, not a measured cumulative saving.

Human thread

A psychology degree, 2009–2012, then a move into software. I still build for organisations with no engineering team.

4A L'Escale ↗

I help relatives caring for people with Alzheimer’s find this respite centre’s activities, information and contacts. A facilitator and webmaster from 2011 to 2018, I have returned as a volunteer software developer in 2026.

Résidence du Verger ↗

To coordinate a residential building’s façade renovation, I built a site that centralises information and makes progress easier to follow. As vice-chair of the co-owners’ council, I use it to keep owners informed, organise the work and respond quickly.

Pierres en Lumières

Sole developer. New version in progress, release planned for Q4 2026 – January 2027.

Let’s talk about your product and how I can help build it.

me@cedric-freret.fr LinkedIn ↗ Paris area · hybrid