# William jums

William jums is a remote worker on Himalayas, Network / Security Engineer at MOSS, based in France.

Source: https://himalayas.app/@williamjums

```text
Network security engineer at MOSS in defense, who built Python tools for firewall migration, rule generation, and ANSSI compliance checks.
```

| Detail | Value |
| --- | --- |
| Availability | Looking for a job |
| Location | France |
| Authorized to work in | France |
| Salary expectations | 75k+ EUR |
| Job categories | Network Security Engineer, AI Engineer |
| Skills | Network Security, Firewall Management, Firewall Migration, SD WAN, IPSEC, ANSSI, Firewall Rule Review, Network Architecture, BGP, OSPF, MPLS, VPN, DDoS Protection, WAF, Proxy and Reverse Proxy |
| LinkedIn | https://linkedin.com/in/william-corenthin |

## About

```text
At MOSS, I ran Stormshield firewalls connecting more than 10 sites across France for a defense client, supporting high-availability IPsec tunnels and enforcing security policies aligned with ANSSI recommendations.

I built three Python tools to reduce repetitive firewall work: an SMC migration toolkit, tools for preparing and comparing flow rules, and first-pass ANSSI compliance checks. They include safeguards such as dry runs, automated tests, and engineer review before generated scripts are used.

At CELINE, I delivered more than 60 EMEA store openings on Meraki SD-WAN, handling network design and connectivity while meeting every opening date. At Société Générale, I contributed to the migration of more than 2,600 branches from MPLS to Cisco Viptela SD-WAN.

My experience also includes F5 BIG-IP proxy and WAF operations at BNP Paribas, anti-DDoS work at Axians CSP, and FortiGate deployments at Intrinsec. I’m currently training in AI engineering and building self-hosted MCP servers and agent skills in my personal projects.
```

## Experience

### Network / Security Engineer

MOSS. Aug 2025 - Jul 2026

```text
Managed Stormshield SNS/SMC firewall estate for a defense client, enforced ANSSI-compliant security policies, and led a major firmware upgrade. Built three internal Python tools for firewall migration, flow opening, and compliance checks.
```

Skills: Stormshield, IPSEC, Python, Paramiko, REST-APIs, Flask, Pytest, Gitlab-CI, HashiCorp-Vault, ANSSI

### Network / Security Engineer

CELINE. Jan 2023 - Dec 2024

```text
Delivered 60+ EMEA store openings on Meraki SD-WAN, including network design, bandwidth sizing, and VLAN configuration. Recovered a store offline mid-migration using temporary internet access and CDP/LLDP.
```

Skills: Cisco-Meraki-SD-WAN, VLAN, WiFi, network-design, Troubleshooting

### Network / Security Engineer

[Société Générale](https://himalayas.app/companies/sg-americas-operational-services-llc). Mar 2020 - Dec 2022

```text
Acted as client-side technical authority for SD-WAN migration of 2,600+ branches from MPLS to Cisco Viptela. Integrated control plane in data centers, set up BGP routing, and supported rollout of ten branches per day.
```

Skills: Viptela, SD-WAN, BGP, Routing, Data-Center, Radware, Run-Books

### Network / Security Engineer

Feducia for CELINE. Jan 2019 - Feb 2020

```text
Migrated 40+ EMEA stores from MPLS to Internet SD-WAN using Meraki, including WAN links, telephony, and fiber backbone.
```

Skills: Cisco-Meraki-SD-WAN, MPLS, WAN, Telephony

### Network / Security Engineer

Axians CSP. Dec 2017 - Jan 2019

```text
Built Wanguard anti-DDoS from scratch using Juniper MX J-Flow and BGP diversion, and tuned thresholds per ISP. Provided level 2/3 support for 20+ hosted clients.
```

Skills: Wanguard, Juniper-MX, BGP, DDoS-Protection, ISP

### Proxy / Reverse Proxy Engineer

BNP Paribas. Dec 2016 - Dec 2017

```text
Sole referent for F5 BIG-IP (VIPs, SSL/TLS, iRules) and WAF tuning across 50+ business applications. Handled 100+ URL-filtering requests with zero-incident production deployments.
```

Skills: F5-BIG-IP, SSL-TLS, IRules, WAF, URL-Filtering

### Network / Security Engineer

Intrinsec. Aug 2015 - Dec 2016

```text
Deployed dedicated FortiGate firewalls in a multi-tenant data center for 30+ clients. Managed VLAN/VPLS across 3 data centers, BGP/OSPF, and Juniper CPE, with on-call rotation.
```

Skills: FortiGate, VLAN, VPLS, BGP, OSPF, Juniper

### Network & Security Administrator

[Crédit Agricole](https://himalayas.app/companies/credit-agricole-group). Jun 2014 - Jul 2015

```text
Managed Juniper firewalls and handled flow openings end to end. Operated LAN on Cisco and HP switching, and administered DNS, DHCP, and IPAM.
```

Skills: Juniper, Cisco, HP-Switches, VLAN, Port-Security-(802.1X), DNS, DHCP, IPAM

## Education

### Cisco

CCNP, Networking. 2016 - 2019

```text
CCNP certification from Cisco, completed between 2016 and 2019.
```

### ETNA

Master's degree (BAC+5), Network, System Architecture & Security. 2016 - 2018

```text
Master's degree (BAC+5) in Network, System Architecture & Security from ETNA, Ivry-sur-Seine, 2016–2018.
```

## Tech stack

- GitLab CI
- Pandas
- Python
- Traefik
- Flask
- Linux
- pytest
- Juniper
- Claude Code
- REST APIs
- Cisco
- HTML

To contact William, message them from this profile with a Himalayas employer account: [Hire on Himalayas](https://himalayas.app/hire).

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