From the blog post of builtinCHI:

100 BEST PLACES TO WORK IN CHICAGO 2021

1. SERVICENOW
   Cloud + Information Technology
2. DRW
   Fintech
3. BELVEDERE TRADING
   Fintech + Information Technology
4. ACTIVECAMPAIGN
   Information Technology + Marketing Tech
5. CHIME
   Fintech
6. The Marketing Store
   Agency + Marketing Tech
7. DFIN
   Fintech + Information Technology
8. CATERPILLAR
   Cloud + Internet Of Things
9. BRAVIANT HOLDINGS
   Fintech
10. EVIVE
    Healthtech + Software
11. ZORO
    Ecommerce
12. IMC TRADING
    Fintech + Software
13. RIGHTPOINT
    Agency + Information Technology
14. OPPLOANS
    Fintech
15. INFUTOR DATA SOLUTIONS
    Adtech + Big Data
16. THOUGHTWORKS
    Software
17. ALLIANT CREDIT UNION
    Fintech
18. WOLVERINE TRADING
    Fintech
19. PARETO INTELLIGENCE
    Big Data + Healthtech
20. RELATIVITY
    Software
21. GRAINGER
    Ecommerce + Retail
22. CLEARCOVER
    Fintech + Insurance
23. FLEXERA
    Cloud + Software
24. MORNINGSTAR
    Enterprise Web + Fintech
25. VIVID SEATS
    Consumer Web + Ecommerce
26. IMANAGE
    Artificial Intelligence + Cloud
27. PANGEA MONEY TRANSFER
    Fintech + Mobile
28. Integral Ad Science
    Adtech + Big Data
29. CAMELO ILLINOIS
    Consumer Web + Ecommerce
30. CENTRO
    Adtech + Software
31. FOURKITES
    Software + Transporation
32. FLEXPORT
    Logistics + Software
33. SILKROAD TECHNOLOGY
    HR Tech + Information Technology
34. KALDEROS
    Healthtech + Machine Learning
35. ENOVA
    Fintech + Machine Learning
36. C.A. FORTUNE
    Marketing Tech + Professional Services
37. NEXTCAPITAL
    Fintech + Software
38. UPWORK
    Cloud + HR Tech
39. REVERB
    Ecommerce + Music
40. SHOWPAD
    Software
41. DISCOVER
    Big Data + Cloud
42. EVERSPRING
    Edtech
43. CSC CORPTAX
    Fintech + Information Technology
44. PERSADO
    Marketing Tech + Software
45. COHEALTH
    Healthtech + Information Technology
46. PEAK6
    Fintech
47. SLALOM
    Information Technology + Professional Services
48. RELAYR
    Artificial Intelligence + Information Technology
49. OTUS
    Big Data + Edtech
50. TRADING TECHNOLOGIES
    Fintech + Information Technology
51. PAYLOCITY
    HR Tech + Software
52. ROOT
    Insurance + Machine Learning
53. G2
    Enterprise Web
54. STRATA DECISION TECHNOLOGY
    Healthtech+ Information Technology
55. MOTOROLA SOLUTIONS
    Software
56. VIBES
    Marketing Tech + Mobile
57. INSPIRETI
    Information Technology + Professional Services
58. SAGGEZZA
    Information Technology + Professional Services
59. ARITY
    Big Data + Transportation
60. KIN + CARTA
    Agency + Cloud
61. BRINGG
    Enterprise Web + Software
62. DIALOGTECH
    Adtech + Marketing
63. SDI PRESENCE
    Information Technology + Professional Services
64. SNAPSHEET
    Mobile + Software
65. CSG
    Internet Of Things + On-Demand
66. AVEPOINT
    Cloud + Information Technology
67. PEAPOD DIGITAL LABS
    Ecommerce + Food
68. TRANSUNION
    Fintech
69. M1 FINANCE
    Consumer Web + Fintech
70. BRAINTREE
    Fintech + Payments
71. VILLAGEMD
    Big Data + Healthtech
72. AMOUNT
    Fintech
73. CITYBASE
    Information Technology + Other
74. ASCENT
    Artificial Intelligence + Enterprise Web
75. SPINS LLC
    Big Data + Cloud
76. PUNCHKICK INTERACTIVE
    Agency + Mobile
77. CARRIERDIRECT
    Information Technology + Logistics
78. KEHE DISTRIBUTORS
    Food + Information Technology
79. DUCK CREEK TECHNOLOGIES
    Cloud + Fintech
80. NEXLP
    Artificial Intelligence + Big Data
81. APERVITA
    Healthtech
82. YELLO
    Enterprise Web + HR Tech
83. NARRATIVE SCIENCE
    Artificial Intelligence + Machine Learning
84. WEST MONROE
    Professional Services
85. AVANT
    Fintech
86. HEALTHJOY
    Healthtech + Insurance
87. TEGUS
    Fintech + Software
88. KENNA SECURITY
    Security + Software
89. LIFE FITNESS
    Fitness + Internet Of Things
90. TOCK
    Food + Software
91. SHOPRUNNER
    Big Data + Consumer Web
92. OPTIVER
    Fintech
93. JELLYVISION
    Software
94. ALL CAMPUS
    Agency + Edtech
95. PRICEFX
    Cloud + Software
96. SPROUT SOCIAL
    Social Media + Software
97. CPI, THE OPENFOX COMPANY
    Software
98. BLACK SPECTACLES
    Ecommerce +Edtech
99. SUPERNOCA
    Cloud + Fintech
100. CARDX
     Fintech + Payments
     

Source: The Best Places To Work