Microservices & event-driven architecture · 10 years · mission-critical systems
10 years of C# / .NET development, from full stack to mission-critical systems. In recent years, focused on microservices with Clean Architecture and event-driven architecture (Kafka), notably in financial environments.
High-availability services handling up to 150,000 transactions/hour with sub-2-second responses. REST API and asynchronous communication via Kafka, containerization on OpenShift.
.NET 8KafkaPostgreSQLOpenShiftTest Containers
2022 — 2023
.NET Developer — Legal Document Generation
Septeo Solutions Notaires
Secure legal document generation features, legal compliance, resolution of production performance issues.
.NET Framework 4.8SQL ServerAzure DevOps
2016 — 2022
Lead Developer then Full Stack — Mission-critical ERP
Neos-SDI · client Stokomani
Operational maintenance of a production ERP (orders, inventory, suppliers), technical team leadership, code review, production T-SQL quick fixes.
C#T-SQLSSIS / SSRSEntity Framework
03
Eager to Master
Solid in backend .NET, curious and eager to level up on other stacks.
My core expertise is backend .NET, but I readily integrate into a project's stack — whether technologies I've already touched and want to deepen, or new ones to discover. Here's what I'm eager to master: a great way to add value while growing my skills.
Angular
To explore
Encountered from afar (mostly AngularJS, the older version); keen to train seriously on a full stack project.
Blazor
Familiar ground
Razor syntax I know from MVC (@Html, server-side views) — a natural bridge to the front end while staying in the .NET ecosystem.
Vue.js
To explore
New to me, but the component approach appeals to me; keen to learn it on a real project.
Next.js / React
To explore
An ecosystem I want to discover; my JS foundation and experience with component architectures make it easy to pick up.
AI / LLM in apps
To explore
Integrating LLMs and AI into business applications: a topic that strongly motivates me and that I already use via Claude Code / Copilot.
App Insights
Touched on
Used for performance monitoring and real-time error management (ERP project); eager to leverage it more deeply, building on my observability experience.
Node.js · PHP · Umbraco
Touched on
Encountered across projects (including an Umbraco 7→10 migration); foundations in place, ready to level up if a project calls for it.
Protobuf · Material Design
Touched on
Used on a test simulator (APRR): Protobuf serialization for inter-service messaging, Material Design for the UI. Keen to practice them further.
Also practiced (legacy):VB.NET, WPF / XAML / MVVM, SSIS / SSRS, KnockoutJS, Infragistics, UWP — technologies encountered on earlier projects, available if a mission requires them.
04
Geographic Range
Full remote, or on-site missions across a wide central-eastern radius.
Based in Le Creusot (Saône-et-Loire, France), I work fully remote or hybrid. Key asset: the Le Creusot TGV station opens up the entire Paris–Lyon axis with direct access, making many on-site missions perfectly viable.
🚄Le Creusot–Montceau–Montchanin TGV station — Paris in 1h17 direct · Lyon in ~40 min direct · trains until evening (≈9:47 PM). Allow ~15 min from Le Creusot to reach the station (Montchanin).
Daily commute — no conditions
≤ 45 min each way — daily on-site presence possible
Chalon-sur-Saône
car →~40 min
TER →~40 min
road / TER
500 €/ day · negotiable
Beaune
TER →~45 min
car →~1h
TER / road
510 €/ day · negotiable
Daily commute — if ≥ 2 remote days
≤ 1h30 each way — daily viable with at least 2 remote days / week
Lyon
Le Creusot →~40 min
TGV direct
+ ~15 min to station (Montchanin)
Round trip same day
out· morning → Lyon in ~40 min
back· until 10:23 PM last departure
520 €/ day · negotiable
Mâcon
car →~1h
road / TGV
510 €/ day · negotiable
Dijon
car →~1h15
TER →~1h· via Beaune
road / TER
520 €/ day · negotiable
Moulins
car →~1h15
road
520 €/ day · negotiable
Bourg-en-Bresse
car →~1h30
road
530 €/ day · negotiable
Weekly on-site base
1h30 to 3h each way — weekday presence, weekly round trip (arrive Sunday evening, return on last on-site day)
Paris
Le Creusot →1h17
TGV direct · 5–6/day
+ ~15 min to station (Montchanin)
Comfortable weekly
out· from 6:53 AM → Paris 8:14 AM
back· until 9:47 PM, arrival ~10:20 PM
640 €/ day · negotiable
🛏 apart-hotel near mission ~1000–1400 €/month
Besançon
car →~2h
road
550 €/ day · negotiable
🛏 apart-hotel / residence ~700–950 €/month
Saint-Étienne
Le Creusot →~1h40
TGV via Lyon
+ ~15 min to station (Montchanin)
560 €/ day · negotiable
🛏 apart-hotel / residence ~650–900 €/month
Clermont-Ferrand
car →~2h15
road
560 €/ day · negotiable
🛏 apart-hotel / residence ~700–950 €/month
Grenoble
car →~2h45
road
570 €/ day · negotiable
🛏 apart-hotel / residence ~750–1000 €/month
Valence
car →~2h15
road
580 €/ day · negotiable
🛏 apart-hotel / residence ~700–950 €/month
Genève / Annecy
car →~2h45
road
640 €/ day · negotiable
🛏 apart-hotel / residence ~950–1300 €/month
Nearby cities, normally daily commute (2 remote days) — but also workable on a weekly on-site base if the mission needs more presence, by taking local lodging. Accommodation counted Sunday evening to Thursday evening (≈ 4 nights/week).
3h–4h each way — alternating on-site presence, remote on the off week
Avignon / Aix
via Lyon →~3h
TGV + transfer
+ ~15 min to station (Montchanin)
1 week in 2 on-site
out· Sun. evening, transfer Lyon
back· last on-site day, evening
600 €/ day · negotiable
🛏 apart-hotel / residence ~400–550 €/month (1 wk in 2)
Marseille
via Lyon →~3h30
TGV + transfer
+ ~15 min to station (Montchanin)
620 €/ day · negotiable
🛏 apart-hotel / residence ~400–600 €/month (1 wk in 2)
Montpellier
via Lyon →~3h30
TGV + transfer
+ ~15 min to station (Montchanin)
620 €/ day · negotiable
🛏 apart-hotel / residence ~400–550 €/month (1 wk in 2)
Travel arrangement. For on-site missions between 1h30 and 3h each way, I work on a weekly basis: arrive Sunday evening, return on the evening of the last on-site day. Beyond 3h, I favor an every-other-week presence with remote work on the intervening week. Late TGV schedules (departures until ~9:47 PM, station open in the evening) make these rhythms reliable year-round toward Paris and Lyon. The TER Mobigo network also serves Dijon, Beaune and Chalon alongside the TGV. Times are indicative — to be confirmed on SNCF Connect depending on the day.
Total travel time. The durations shown are door-to-door estimates. The trip between the arrival station and the mission site (by transit) adds to the total: if this addition exceeds a category's ceiling, the city moves to the next category. Beyond 4h total, the mission isn't retained. A mission site close to the station is therefore a real plus.
Day rate. Rates indicated for a long mission, negotiable depending on duration, context and technical scope. Fully remote: €500 / day. On-site rates include travel and accommodation in an apart-hotel / lease-free residence (flexible booking, no application file or deposit, services included). For every-other-week presence, accommodation is only booked on the on-site weeks (monthly cost reduced accordingly). Open to umbrella-company arrangements.
05
Terms & Preferences
What makes a collaboration run smoothly on both sides.
Status
Freelance
Open to umbrella-company arrangements
Availability
From Sept. 7, 2026
Long missions welcome
Focus areas
Microservices · Full stack
Modern .NET, event-driven, finance
Work mode
Remote or hybrid
On-site possible (see range)
Methodology
Agile / SCRUM
TDD / BDD, code review
Languages
FR native · EN B2
Comfortable with technical discussions in English
A technically demanding mission?
Let's talk. I respond quickly and can share my availability and references.
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Last updated: July 2026
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Baptiste Lejeune — sole trader (French auto-entrepreneur), registered under SIRET 843 437 088 00019. Le Creusot, France. Contact: baplej@gmail.com · +33 6 47 23 27 55.
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