Our Job Offers

Request : 

We are looking for a skilled Firmware Developer to join our R&D team in a fast-growing startup environment. In this role, you will not only develop cutting-edge firmware for embedded systems and transceivers but also contribute directly to the growth and success of the company. 

Estel develops and manufactures optical transceivers in Europe and is the first company to re-establish transceiver manufacturing on the continent. By joining our team, you will actively help bring transceiver production back to Europe, strengthening local industry and increasing European competitiveness in the global telecom and datacom markets. 

You will work across the full firmware development lifecycle - from concept and feasibility studies to design, implementation, bring-up, and validation on target hardware. This is a unique opportunity to combine hands-on technical development with strategic impact in a dynamic startup environment, where time-to-market is critically important and every contribution counts. 

Key Responsibilities : 

Participate in feasibility studies and concept development by evaluating product requirements and drafting initial FW architecture. 

Collaborate with hardware and system engineers to plan FW development and sprint planning using Scrum methodology. 

Design and implement firmware for different type of optical transceivers, including peripheral drivers, communication interfaces (I2C, SPI, UART), and device control logic. 

Implement host interfaces based on CMIS/MIS standards to ensure proper communication and interoperability with external systems. 

Develop firmware ahead of first hardware availability using emulators (e.g., QEMU) or evaluation boards to accelerate board bring-up. 

Conduct firmware bring-up and debugging on prototype modules using lab instruments such as oscilloscopes, multimeters, logic analyzers, and protocol sniffers. 

Execute firmware validation and DVT (Design Verification Test) to ensure all functional requirements are met. Implement incremental firmware features based on testing results and provide ongoing support for integration and system-level testing. 

Collaborate with cross-functional teams to review test data, troubleshoot issues, and optimize FW performance. 

Qualifications :  

Required :  

• Bachelor’s or Master’s Degree in Computer Engineering, Electrical Engineering, or similar. 
• 3-4 years of experience in embedded firmware development and testing, preferably on ARM microcontrollers, including RTOS-based systems. Programming: C/C++, Python 
• Good knowledge of I2C, SPI, UART, MDIO, J-Link and JTAG/SWD debugging. 
• Very familiar with typical FW development tools like e.g. GIT, Bitbucket, Jira, Jenkins and unit testing frameworks. 
• Experience with schematic review and basic hardware verification. 
• Familiarity with board bring-up, debugging, and integration testing on embedded hardware. 
• Good understanding of the overall development process  
• Experience of agile development methods in general and Scrum in particular 
• Strong analytical, problem-solving, and communication skills; team player with self-motivation. 

Preferred : 

• Any experience in pluggable optics development or familiarity with standard optical equipment such as OSAs, power meters, amplifiers, VOAs, and BER instruments is an advantage. 
•  Language: Swedish, Spanish, or French is an advantage

Workplace  

TechPark Malaga Spain 

Reporting

The Firmware engineer reports to the Project manager and --- CTO. 

Contact person
hr@e-s-tel.com 

Request :

Estel is now looking for an NPI Engineer for our Production line in Chastrès, Belgium. The NPI Engineer will support the development and industrialization of advanced optical transceiver modules. The ideal candidate will have strong experience in mechanical design, optical module packaging, assembly processes, and NPI execution. Experience of FAU (Fiber Array Unit) machines for optical alignment, fibre attach, and precision assembly is a merit. 

This role is highly cross-functional, working closely with R&D, optics, electronics, reliability, and manufacturing teams to bring optical transceiver designs from prototype to mass production. 

Key Responsibilities :

Mechanical & Packaging Engineering 

Perform geometric, tolerance analysis, and material selection for precision assembly. 

Collaborate with electrical, optical and thermal engineers to ensure robust system integration. 

Optical Module Assembly & Process Development 

Develop and qualify assembly processes such as: 

• Fiber attach and optical alignment (active and passive) 
• FAU, PM fibre, PIC, glass interposer handling, placement, and bonding 
• Soldering, epoxy dispense/cure, laser welding, cleaning 
• Component assembly such as lens, isolator, connector mating, hermetic sealing. 

Define assembly jigs, fixtures, and tooling for NPI and mass production. 

Conduct process capability studies and drive DFM/DFA improvements. 

NPI Execution 

Lead NPI builds for transceiver modules, from EVT/DVT into pilot and MP. 

Operate, configure, and troubleshoot FAU NPI machines for test runs and engineering builds. 

Develop SOPs, WI, BOMs, ECNs, and process documents. 

Support FA (Failure Analysis) and root cause investigations for yield and performance issues. 

Interface with CM partners to ensure smooth production transfer. 

FAU NPI Machine Operation & Optimization 

Operate FAU automated equipment for: 

• Fiber alignment 
• Fiber attach (UV/thermal bonding) 
• Optical coupling validation 

Optimize machine recipes, bonding parameters, and alignment algorithms. 

Monitor machine performance, diagnose issues, and work with vendors for maintenance or upgrades. 

Train technicians and operators on best practices for FAU-based assembly processes. 

Qualifications:  

Required :  

• Master's degree in mechanical engineering, Opto-Mechanics, Mechatronics, or related field. 
• 3+ years’ experience in photonics assembly, packaging, opto-mechanical design, or NPI. 
• Hands-on experience operating or developing processes on FAU / fiber attach NPI machines. 
• Strong CAD experience (SolidWorks, Creo, or equivalent). 
• Familiarity with GD&T, tolerance stack-up, precision mechanics, and optical coupling principles. 
• Working knowledge of DFM, DFA, SPC, and NPI process flows. 
• Language: English on C1 Advanced to C2 Proficient level 

Preferred : 

• Experience with PIC, Optical component packaging, micro-optics, active alignment, and optical test. 
• Knowledge of QSFP, OSFP, SFP, CFP, or other telecom/datacom multisource agreement form factors. 
• Experience with high-volume optical component manufacturing. 
• Driver License. 

Workplaces 

4 Allée des Plantains, 5650 Chastrès Belgium 

Reporting 

The NPI engineer reports to the Production Manager and --- CTO. 

Contact person 
hr@e-s-tel.com 

Request :

Estel is now looking for a Sales Director for Telecom Operators responsible for leading and expanding strategic sales activities with global and regional telecom carriers (Tier 1, Tier 2, and alternative operators). This role combines deep market understanding of optical networking with strong commercial leadership to drive revenue growth, secure long-term partnerships, and position the company as a preferred supplier of optical transceiver solutions.

The Sales Director will manage key accounts, develop strategic sales plans, coordinate cross-functional teams, and ensure successful execution of high-value commercial engagements.

This role is highly cross-functional, working closely with R&D, optics, electronics, reliability, and manufacturing teams to bring optical transceiver designs from prototype to mass production. 

Key Responsibilities :

Strategic Sales Leadership

• Develop and execute a comprehensive sales strategy targeting telecom operators globally or regionally.

• Identify growth opportunities in 5G, FTTH, metro/core networks, data transport, coherent optics, and emerging technologies.

• Lead full-cycle sales activities from opportunity identification to contract negotiation and closure.

Account Management & Customer Development

• Own executive-level relationships with telecom operators, including procurement, engineering, and network strategy teams.

• Build a multi-year account plan to increase share of wallet and strengthen vendor positioning.

• Gather customer requirements and influence product roadmaps in alignment with operator needs.

Revenue & Pipeline Growth

• Drive sales performance to meet or exceed revenue, margin, and volume targets.

• Manage accurate forecasting, funnel management, and quarterly business reviews.

• Lead the preparation of commercial proposals, RFQs/RFPs responses, and long-term supply agreements.

Cross-Functional Collaboration

• Work closely with product management, engineering, marketing, operations, and executive leadership.

• Translate customer requirements into clear technical and operational actions.

• Coordinate with supply chain teams to optimize allocation, lead times, and delivery performance.

Market & Competitive Intelligence

• Monitor market trends such as coherent evolution, 400G/800G transitions, pluggable optics, disaggregation, and ROADM architectures.

• Track competitor positioning, pricing strategies, and technology roadmaps.

• Provide insights to support strategic decisions and product differentiation.

Qualifications & Experience

Required

• 10+ years of sales experience in telecom, optical networking, or related telecom hardware sectors.

• Proven success managing large accounts in Tier 1/Tier 2 operators.

• Deep knowledge of optical transceivers, DWDM systems, coherent optics, switching/routing ecosystems, and operator procurement cycles.

• Strong negotiation skills and ability to close multi-million-dollar contracts.

• Excellent communication skills with the ability to manage C-level relationships.

Preferred

• Experience in an optical module or photonics manufacturing company.

• Understanding of technical standards (IEEE, ITU-T, OIF) and optical module form factors (SFP/SFP+, QSFP28/56/112/DD, CFP/CFP2/CFP4, OSFP).

• Familiarity with global telecom infrastructure trends: 5G transport, broadband rollout, open/ disaggregated optical networks.

• MBA or advanced business/technical degree.

Workplaces 

Onsite or remote 

Reporting 

The Sales Director reports to the Sales Manager and C-level

Contact person 
hr@e-s-tel.com 

Request :

Estel is now looking for a junior Opto-mechanical Engineer for our Production line in Chastrès, Belgium. The Opto-mechanical Engineer will work on opto-mechanical systems to support the development and industrialization of advanced optical transceiver modules. The ideal candidate will have good knowledge in mechanical design, optical module packaging, assembly processes, and NPI execution. If possible, some experience of FAU (Fiber Array Unit) machines for optical alignment, fibre attach, and precision assembly is a merit. This role is highly cross-functional, working closely with R&D, optics, electronics, reliability, and manufacturing teams to bring optical transceiver designs from prototype to mass production.  

Trainings :

The junior Opto-mechanicalengineer will attend formative sessions within the company departments:  

It will include:  

- Production training at the Fab in Belgium and later on work on FAU NPI machine and others.  

- Training in Stockholm Sweden to learn some key concepts with our R&D team.  

- Multiple trips to Germany (Aachen or Bremen) to work on production FAU machine development with our machine builder.   

 Key Responsibilities:

- Mechanical & Packaging Engineering 

Perform geometric, tolerance analysis, and material selection for precision assembly. Collaborate with electrical, optical and thermal engineers to ensure robust system integration.   

- Optical Module Assembly & Process Development 

Develop and qualify assembly processes such as: Fiber attach and optical alignment (active and passive) FAU, PM fibre, PIC, glass interposer handling, placement, and bonding Soldering, epoxy dispense/cure, laser welding, cleaning Component assembly such as lens, isolator, connector mating, hermetic sealing.  Define assembly jigs, fixtures, and tooling for NPI and mass production. Conduct process capability studies and drive DFM/DFA improvements.  

- NPI Execution 

Lead NPI builds for transceiver modules, from EVT/DVT into pilot and MP. Operate, configure, and troubleshoot FAU NPI machines for test runs and engineering builds. Develop SOPs, WI, BOMs, ECNs, and process documents. Support FA (Failure Analysis) and root cause investigations for yield and performance issues. Interface with CM partners to ensure smooth production transfer.  

FAU NPI Machine Operation & Optimization 

Operate FAU automated equipment for: Fiber alignement Fiber attach (UV/thermal bonding) Optical coupling validation Optimize machine recipes, bonding parameters, and alignment algorithms. Monitor machine performance, diagnose issues, and work with vendors for maintenance or upgrades. Train technicians and operators on best practices for FAU-based assembly processes.  

Qualifications:  

Required:  

- Master's degree in Opto-Mechanics, Mechanical engineering, Mechatronics, or related field.

- 0- or 1-year experience in photonics assembly, packaging, opto-mechanical design, or NPI. 

- Familiarities with optical alignment processes, FAU / fibre attach NPI machines. - 

- Familiarity with GD&T, tolerance stack-up, precision mechanics, and optical coupling principles. 

- Working knowledge of DFM, DFA, SPC, and NPI process flows. 

- Language: English on C1 Advanced to C2 Proficient level.  

Preferred: 

- Knowledge of PIC, Optical component packaging, micro-optics, active alignment, and optical test. 

- Knowledge of QSFP, OSFP, SFP, CFP, or other telecom/datacom multisource agreement form factors. 

- Knowledge of high-volume optical component manufacturing. 

- CAD experience (SolidWorks). 

- Driver License.  

Workplaces 
HQ Belgium :  

4 Allée des Plantains, 5650 Chastrès Belgium 

Estel R&D center:  

Estel, CONVENDUM  Vasagatan 14A  Box 1051  SE-172 61 Sundbyberg Sweden  

FAU Machine Builder (Project based) :  

Aachen or Bremen, Germany  

Reporting 

The NPI engineer reports to the Production Manager and --- CTO.  

Contact person 
hr@e-s-tel.com 

Request : 

Estel is now looking for a Product Line Manager (PLM). The PLM acts as the business and technical owner of a product family, bridging Market, Engineering, Operations, and Customers. He will manage the full lifecycle of our optical transceiver portfolio from opportunity assessment to market introduction ensuring ESTEL delivers differentiated, high-quality products that meet customer and industry requirements. 

This role requires strong technical understanding of optical networking (Layer 0/1), the ability to collaborate with engineering teams (including FPGA, embedded SW, systems architecture), and the skill to translate market needs into clear product requirements. 

This role is highly cross-functional, working closely with R&D, sales, operations and manufacturing teams to bring optical transceiver designs from prototype to mass production.  

Key Responsibilities 

• Product Strategy & Roadmap 

Define and own the product vision, market positioning, and multi-year roadmap for optical transceivers and related solutions. 

Analyze market trends (DCI, Metro, Long-Haul, coherent optics, pluggable, 100G–1.6G and beyond evolution). 

Benchmark competition and identify differentiation opportunities.  

Perform business case analysis including ROI calculation per product.

• Product Requirements 

Develop Product Requirement Documents (PRDs) and System Requirements in collaboration with Engineering and QA. 

Translate customer requests (RFP/RFI/RFQ) into clear functional and technical specifications. 

Prioritize features based on cost, feasibility, and market impact.  

Cross-Functional Leadership Work closely with R&D (FPGA, hardware, firmware, system architecture), Operations, and Sales to drive development milestones. 

Support project management activities and monitor execution vs. plan. 

Ensure products meet compliance standards and MSA specifications.  

• Customer & Market Engagement 

Assist Sales in technical discussions with Tier-1 operators, data centers, and OEM customers. 

Present roadmap, lead workshops, and support key accounts during evaluation and certification processes. 

Provide escalation support for troubleshooting, release validation, and field issues when needed.  

• Lifecycle Management 

Oversee the complete product lifecycle: concept → development → launch → maintenance → phase-out. 

Manage pricing strategy, cost optimizations, and profitability targets. 

Drive Type Approvals and interoperability testing.  

Qualifications:  

Required:  

Degree in Engineering Physics, Electrical/Telecom Engineering, or similar. 

5+ years' experience in optical networking, transmission systems, or hardware/software product development. 

Understanding of Layer 0/1 technologies (OTN, SDH, Ethernet, coherent transmission, optical modulation). 

Experience in System Architecture or Systems Engineering (e.g., requirement writing, modeling, Jira/Git workflows). 

Strong communication skills and ability to interact with customers, engineering teams, and executives. 

Fluent in English; additional European languages are a plus. 

Swedish or Belgian work permits 

Preferred : 

Hands-on knowledge in optical network design (Metro, DCI, Long-Haul). 

Experience with FPGA, Verilog/VHDL, embedded systems or hardware-software integration. 

Ability to understand and challenge technical design decisions. 

Background in technical sales, customer support, or network troubleshooting. 

Familiarity with coherent DSPs, pluggable form factors (QSFP-DD, OSFP), and emerging technologies (800G+).  

Workplaces : 

Depending on his location the candidates could be working either in Sweden or Belgium 

R&D Office Sweden:  

Estel, CONVEDUM Vasagatan 14A Box 1051 SE-172 61 Sundbyberg Sweden 

HQ & Production Line Belgium:  

4 Allée des Plantains, 5650 Chastrès Belgium  

Reporting : 

The PLM Manager reports to the CTO, Sale Manager --- Production Manager --- CEO

Contact person :  

hr@e-s-tel.com