Coming in to 2020, most firms probably would have had Brexit at the forefront of their minds, as the deal struck between the EU and UK last year left most of its major questions unanswered.
However the future of trade across the Irish Sea became a minor distraction to many by March, as the arrival of Covid-19 to these shores spun many firms into a fight for survival.
There were some winners, particularly in technology, as our devices and broadband connections became more important than ever.
Meanwhile many smaller firms found novel ways to remain afloat in spite of the existential crisis facing them.
And the Government was forced to undertake an unprecedented programme of supports for the economy - spending big in an attempt to secure jobs in the longer term.
In this year's Business Year in Review, RTÉ Business takes a look, over seven days, at seven ways in which the Irish and global economy was changed fundamentally in 2020, starting today with the extraordinary challenges faced by aviation.