How many employees work at ESO?
Electricity System Operator has approximately 717 total employees worldwide as of March 2026, according to Revelio Labs workforce intelligence data. ESO's total headcount has grown 3.1% from 696 employees in 2023 to 717 in 2026.
Data source: Revelio LabsCoverage: Global workforce, 2023–2026Published June 2026
About ESO's Workforce
Electricity System Operator is an Energy and Resources company that employs 717 people worldwide as of March 2026. It is the 8th-largest by headcount among its peers. Founded in 2007, the company is headquartered in Sofia, Bulgaria.
ESO's workforce has grown 3.1% from 2023 to 2026. It fell to a low of 686 in 2023 Q3 before recovering. Its workforce is concentrated most in Bulgaria (98.2%), followed by Morocco (0.6%) and Liberia (0.6%), with Bulgaria, its fastest-growing location.
ESO's largest functional groups are Engineering (50.8%), Finance and Operations (36.1%), and Sales and Marketing (13.1%), with Engineering growing fastest (up 1.3%). Median employee tenure is 7.1 years. The average salary is $23,759, highest in Eastern Europe at a median of $21,000.
Overall employee sentiment is positive and broadly stable.
Sourced from Revelio Labs workforce data.
As of March 2026
ESO
workforce metrics
Headcount
717
0.0% YoY
Avg. Salary
$23.8k
2.0% YoY
Tenure
7.1yr
0.3yr YoY
Growth Rate
0.0%
3.1pts YoY
Hiring Rate
Attrition Rate
Unlock hiring rate, attrition rate, and 12 additional workforce metrics for ESO. Compare to peers, export the dataset, and access the full quarterly history.
- ESO had 717 employees in 2026, a 0% no change from 2025.
- ESO had 719 employees in 2025, a 1.3% increase (+9) from 2024.
- ESO had 710 employees in 2024, a 2.6% increase (+18) from 2023.
- ESO had 692 employees in 2023, a 2.5% increase (+17) from 2022.
ESO's total workforce has grown from 696 employees in 2023 to 717 in 2026.
Electricity System Operator — quarterly employee count (2023–2026)
| Year | Qtr | Employees | YoY Change | YoY % |
|---|---|---|---|---|
| 2026 | Q1 | 717 | +0 | +0.0% |
| 2025 | Q4 | 719 | +9 | +1.3% |
| 2025 | Q3 | 731 | +26 | +3.7% |
| 2025 | Q2 | 716 | +15 | +2.1% |
| 2025 | Q1 | 717 | +22 | +3.2% |
| 2024 | Q4 | 710 | +18 | +2.6% |
| 2024 | Q3 | 705 | +19 | +2.7% |
| 2024 | Q2 | 701 | +5 | +0.8% |
| 2024 | Q1 | 695 | +13 | +1.8% |
| 2023 | Q4 | 692 | +17 | +2.5% |
| 2023 | Q3 | 686 | +24 | +3.5% |
| 2023 | Q2 | 696 | +27 | +3.9% |
Want to see ESO's complete headcount history back to 2017, including quarterly breakdowns?
Bulgaria accounts for the largest share of ESO's global workforce with approximately 98% of total employees, followed by Morocco and Liberia.
ESO employees by country — 2026
| Country | Employees | % of Total | YoY % |
|---|---|---|---|
| Bulgaria | 697 | 98.2% | +0.3% |
| Morocco | 4 | 0.6% | +0.0% |
| Liberia | 4 | 0.6% | +0.0% |
| Poland | 3 | 0.4% | +0.0% |
| Latvia | 2 | 0.2% | +0.0% |
Drill into city-level data, hiring trends by region and historic geographic shifts
ESO's largest employee groups are Engineering (50.8%), Finance and Operations (36.1%), and Sales and Marketing (13.1%).
ESO employees by department — 2026
| Department | Employees | % of Total | YoY % |
|---|---|---|---|
| Engineering | 361 | 50.8% | +1.3% |
| Finance and Operations | 256 | 36.1% | +0.5% |
| Sales and Marketing | 93 | 13.1% | -5.6% |
Compare ESO's department mix to industry peers.
ESO's average employee salary is $23,759 globally. Employees in Eastern Europe receive the highest compensation.
ESO median employee salary by region — 2026 (USD)
| Region | Median Salary |
|---|---|
| Eastern Europe | $21,000 |
Unlock salary by role, level, and city — and compare to ESO's industry peers.
Revelio Labs tracks employee sentiment across ESO's workforce based on public professional data. Overall sentiment is positive and has held steady year over year in 2026.
Overall
Unlock the full sentiment breakdown by department, tenure, and trend over time.
Similar Energy and Resources Companies by Employee Count
- How fast is ESO growing?
- In 2026, ESO's headcount grew 0.0% to 717 employees.
- Where are ESO employees located?
- Most ESO employees are based in Bulgaria (98.2% of headcount), followed by Morocco and Liberia.
- What is the average salary at ESO?
- The average employee salary at ESO is approximately $23.8k per year.
- When was ESO founded and where is it headquartered?
- ESO was founded in 2007 and is headquartered in Sofia, Bulgaria.
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